Mattias Benninge has produced a script, and posted on CodePlex, that allows you to generate Maintenance Windows for ConfigMgr 2012 and 2007.
From the CodePlex page:
This script will create Maintenance Windows in Configuration Manager 2012 (or 2007). It will create a non-reoccurring Maintenance Window with the specified options. There is also an option to create Maintenance Windows based on “Patch Tuesday” or with an offset of days from “Patch Tuesday”. This is useful when for example second Thursday of a month occurs before second Tuesday (see may 2013 as an example).
Download: New-CMMaintenanceWindow 1.0